CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from German Patent Application No. 198 25 065.7, filed Jun. 4, 1998.
The present invention relates to a foil-bag producing and packing apparatus, in particular for foil bags for beverages, the apparatus comprising at least two feed means for feeding the foil material, a connecting means for connecting said foil materials and a cutting means for cutting the connected foil materials into individual foil bags, and to a method for producing and packing foil bags.
Foil bags are used for receiving filling material, such as beverages. Such foil bags consist e.g. of two side foils which are connected, e.g. sealed or welded, to each other at two opposite edges. A bottom foil which in the folded-apart state constitutes a standing base and forms a space for the filling material between the side foils is inserted between the corresponding third edges.
In a foil-bag producing process, at least those two foils are supplied that serve as side foils of the foil bag. The foils are normally supplied in one piece by corresponding supply rolls. The individual foils are placed one upon the other and are sealed or bonded to each other at least at the place where the side edges of the foil bag are located. The interconnected foil webs are then cut along the connections to form individual foil bags. The foil bags produced in this manner, which are closed at three side edges, can e.g. directly be supplied to a filling station in which the filling material is filled in through the fourth edge that has not been closed yet, and are then sealed or bonded.
However, the foil bags which are already closed at three sides can also be united in a packing unit, stacked and transported to a different place in order to be filled.
It is here very important that a high packing density as well as a high stacking accuracy are achieved to keep the transportation volume as small as possible.
It is the object of the present invention to provide an improved foil-bag producing and packing apparatus and a corresponding method by which it is possible to cut the interconnected foils in an easy and reliable manner and to pack the individual foil bags in a uniform manner, whereby a high throughput rate is to be achieved.
According to the invention the foil-bag producing and packing apparatus comprises a cutting means including a substantially vertically moving cutting edge which cuts the interconnected foils along the connecting portions into individual foil bags, the cutting edge cutting the whole foil width of the connected foils which are intermittently supplied by a conveying means. Moreover, the apparatus according to the invention comprises a receiving means in which the cut-off foil bags are stacked for further use and in which directly after the cutting process the foil bags are stored and stacked by a storing device substantially in the direction of movement of the cutting edge.
According to the method of the invention the interconnected foil bags are cut by a cutting edge along the connecting portions to form individual foil bags, and the cut-off foil bags are stacked by a storing device substantially in the direction of movement of the cutting edge directly after the cutting operation.
The substantially vertical movement of the cutting edge makes sure that the flexible foil material is bent during the cutting process to a degree which is as small as possible. The cut foil material is stored and stacked in a receiving means directly downstream of the cutting device. The storing operation is performed in the direction of movement of the cutting edge, whereby the direction of the cut-off foil bags need not be changed and an optimum, time-saving and direct storage is made possible. The direction of movement of the cutting edge through the foil material predetermines the corresponding direction of movement which is continued by the storing device. As a result, the packing process is accelerated.
The individual foils can be adhesively connected or hot-bonded to one another to form the foil bags. A particularly advantageous embodiment of the apparatus according to the invention comprises, however, a sealing means as a connecting means so that when the method according to the invention is performed with the apparatus of the invention, weld seams can be formed along the connecting portions. Such weld seams reliably seal the foils to one another and permit a simple cutting process which can be performed in a reliable manner.
The cutting means can be driven with the help of an electromagnetic drive or a mechanism. Of particular advantage is however an embodiment in which the cutting means comprises a pneumatic means controlled at the same rate as the conveying means for moving the cutting edge. Such a pneumatic means permits a very fast cutting process in a reliable and inexpensive manner.
Depending on the respective requirements, the feed direction of the foils and the direction of movement of the cutting edge may differ. Of particular advantage is however a foil-bag producing and packing apparatus in which the conveying means moves the interconnected foils in a horizontal direction and in which the cutting edge moves in a direction substantially vertical thereto. Such an arrangement guarantees a reliable transportation of the foils and a simple storing mechanism which is in the same direction as the direction of movement of the cutting edge.
It is of particular advantage when the foil bags are additionally pressed together during the stacking operation, whereby the packing volume is further reduced. To this end, the stacking device in the apparatus of the invention may comprise elements which are moved at the same rate as the cutting means and which compress already stacked foil bags. Such elements guarantee a reliable transportation of the cut-off foil bags to the already stacked foil bags and additionally compress the same.
The elements may be moved by a separate drive at the rate of the cutting means. A reliable stacking of the cut-off foil bags, which is independent of the length of the movement of the cutting means, is thereby made possible.
In another, particularly simple embodiment, the elements are directly connected to the cutting edge of the cutting means and are moved together with said means. An additional drive for the stacking elements is thus not necessary.
The apparatus of the invention is particularly reliable when a plurality of adjacent fingers are provided in the storing device for storing the cut-off foil bags in the receiving means.
If the fingers are directly connected to the cutting edge of the cutting means, flexible plastic fingers constitute inexpensive and reliable means which by virtue of their flexibility stack the foil bags in a gentle manner.
In a simple embodiment the conveying means comprises at least one intermittently rotating roller which conveys the connected foils by frictional grip.
The method can be performed on a foil web whose width exactly corresponds to one foil bag. A particularly economic design is however achieved when foil webs are processed the width of which corresponds to a plurality of foil bags so that the individual processing steps can be taken on a plurality of foil bags at the same time. To this end, the feeding means, the connecting means, the cutting means and the storing device of the apparatus according to the invention can be designed such that it is possible to process foils of one width whose dimensions correspond to a plurality of foil bags in a direction perpendicular to the supply direction, and a dividing means is additionally provided upstream of the cutting means for cutting the connected foils into parts which in a direction perpendicular to the conveying direction corresponds to the dimension of a foil bag in a direction perpendicular to the conveying direction.
The cutting means of the apparatus of the invention serves to divide the foil web in a direction perpendicular to the feed direction. If foils of one width are processed, with the foils corresponding to a plurality of foil bags, a corresponding number of foil bags is always cut off by the cutting means from the foil web in one operation. A dividing means which is provided in front of the cutting means serves the purpose that the foil web is already divided in front of the cutting means in feed direction and that individual foil bags are thus present after the cutting means has been passed through.